Refactor ConferenceCard layout

Change the layout of the ConferenceCard component to display information in a single column instead of two columns. This improves readability and presentation.

src/components/ConferenceCard.tsx

@@ -45,7 +45,7 @@ const ConferenceCard = ({
         {full_name && <p className="text-xs text-neutral-600 truncate">{full_name}</p>}
       </div>
       
-      <div className="grid grid-cols-2 gap-x-4 gap-y-2 mb-3">
+      <div className="flex flex-col gap-2 mb-3">
         <div className="flex items-center text-neutral">
           <CalendarDays className="h-4 w-4 mr-2 flex-shrink-0" />
           <span className="text-sm truncate">{date}</span>